The present invention relates to police activity transponders.
Most cars and light trucks on the road today have on-board diagnostic (OBD) systems. In an effort to met Environmental Protection Agency (EPA) emission standards, manufacturers started using electronic engine management to control engine functions and diagnose engine problems during the 1970""s and early 1980""s. Through the years, on-board diagnostic systems came into being and have recently become more sophisticated. OBDII, a standard introduced in the mid-1990""s, provides almost complete engine control and monitoring of other parts of the vehicles including the chassis, body and accessory devices, as well as providing a diagnostic control network for the vehicle.
The origin of these systems date back to 1966 when, in an effort to reduce smog in the Los Angeles Basin, the State of California began requiring emission controls on 1966 model cars. Later, in 1968, the federal government extended these controls nationwide. In 1970, Congress passed the Clean Air Act and established the Environmental Protection Agency (EPA). In doing so, Congress charged the EPA with reducing emissions from cars and trucks. The EPA then promulgated a series of emission standards for motor vehicles to meet this mandate. These standards were graduated, becoming ever more stringent on vehicle emissions with time. Further, manufacturers were required to maintain the vehicle within the emission standards for the useful life of the vehicle.
Manufacturers, in an effort to meet these standards, introduced electronic engine management systems that control engine ignition and fuel delivery. These systems included sensors for monitoring various engine parameters. The ignition and fuel delivery are adjusted based on sensor readings so that vehicles comply with the emission standards. Access to these sensors for diagnostic purposes was also provided.
In the beginning each automotive manufacturer had their own engine management system and used signals commensurate with their system. Finally, in 1988, the Society of Automotive Engineers (SAE), established a set of standards for a connector plug and a set of diagnostic test signals. The EPA adapted most of these standards established by the SAE regarding on-board diagnostic programs, as well as some other recommendations. OBDII is an expanded set of standards and practices developed by SAE and adopted by the California Air Resources Board (CARB) and the EPA. The deadline for implementation of OBDII was Jan. 1, 1996.
Manufacturers began incorporating OBDII standards into various models as early as 1994, although some of these early vehicles were not completely compliant with OBDII standards. However, all vehicles manufactured since Jan. 1, 1996 are compliant with the OBDII standard. OBDII provides a universal inspection and diagnosis method to ensure the vehicle is performing to original equipment manufacturer (OEM) standards. A scanner console or tool is connected to the OBDII connector to inspect and diagnose the vehicle.
There are currently three basic protocols in use, each with minor variations on the communication pattern between the on-board diagnostic computer and the scanner console or tool. While there have been some manufacturer changes between protocols in the past few years, as a rule of thumb, Daimler Chrysler products and all European and most Asian imports use International Standards Organization (ISO) 9141 circuitry. General Motors uses SAE J1850 VPW (Variable Pulse Width Modulation), and Ford Motor Company uses SAE J1850 PWM (Pulse Width Modulation) communication patterns.
It is also possible to tell which protocol is used on a specific automobile by examining the dash connector socket. If the connector has a pin in the #7 position and no pin at #2 or #10, then the vehicle has the ISO 9141 protocol. If no pin is present in the #7 position, the vehicle uses a SAE protocol. If there are pins in positions #7 and #2 and/or #10, the vehicle may still use the ISO protocol. While there are three OBDII electrical connection protocols, the command set is fixed according to the SAE J1979 standard.
Pre-OBDII cars had connectors in various positions under the dashboard and hood. However, as part of the standard, all OBDII vehicles have a connector located in the passenger compartment, easily accessible from the driver""s seat. Often, the connector is located under the dash or behind or near the ashtray. A cable is plugged into the OBDII J1962 connector and connected to a scanner console or scan tool. This equipment ranges from a simple hand-held meter that provides a coded readout of the various diagnostic functions, up to a large console computer-based unit costing thousands of dollars.
These large units are compatible with all cars and contain software that analyzes the signals received from the car, displays a text or diagramed readout of any malfunctions found and suggests possible solutions to the problems.
Smaller units for the home or small shop technician can provide a variety of levels of data, some approaching the sophistication of the big shop consoles. However, they are usually limited to one OBDII system type, unless adapters can be purchased.
OBDII signals are most often sought in response to a xe2x80x9cCheck Engine Lightxe2x80x9d appearing on the dashboard or driveability problems experienced with the vehicle. The data provided by OBDII can often pinpoint the specific component that has malfunctioned, saving substantial time and cost compared to guess-and-replace repairs. Scanning OBDII signals can also provide valuable information on the condition of a used car.
There are other methods to gather data from a vehicle other than using OBDII. One method involves the development of the Intelligent Vehicle Data Bus (IVDB). The IVDB allows all computers within a vehicle to communicate with each other, and potentially makes data used or held by those computers available across the IVDB.
The present invention provides a method of operating a police activity transponder that utilizes data available from a vehicle on-board diagnostic system or intelligent vehicle data bus.
In accordance with a first aspect of the present invention, a police activity transponder is configured to read speed data available through an OBDII interface or IVDB and adjust the sensitivity of the police activity transponder to law enforcement signals based on the speed data.
In accordance with a second aspect of the present invention, a police activity transponder is configured to read speed data available through an OBDII interface or IVDB and using an internal clock, calculate a 0 to 60 mile per hour or a quarter mile time for display.
In accordance with a third aspect of the present invention, a police activity transponder is configured to read speed data available through an OBDII interface or IVDB and function as a speedometer.
In accordance with a fourth aspect of the present invention, a police activity transponder is configured to read engine revolutions per minute (rpm) data available through an OBDII interface or IVDB and function as a tachometer.
In accordance with a fifth aspect of the present invention, a police activity transponder is configured to allow a user to enter a shift point based on engine rpm, read engine rpm data available through an OBDII interface or IVDB, and provide an indication to the user based on a comparison of the engine rpm data and the shift point.
In accordance with a sixth aspect of the present invention, a police activity transponder is configured to read an OBDII vehicle communication protocol and display diagnostic trouble codes.
The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.